1. Field of the Invention
The present invention relates to a liquid preparation which contains lipophilic material that excels in storage stability and has no water-insoluble material (precipitates and lees) even after long storage.
2. Description of the Related Art
Many compounding techniques which arrange liquid medication, injections, cosmetics, etc. in a stable condition in which lipophilic materials are not separated over time have been proposed because lipophilic material in general is poorly-soluble in water and it is likely to separate over time even when dispersed uniformly in water at the beginning. Proposals relating to tocopherol exceptionally dominates among these proposals, for example, a solubilizing solution consisting of 3 ingredients, tocopherol, polyoxyethylene derivative of hydrogenated castor oil and polyglycerin fatty acid ester has been disclosed (Japanese Patent Application Laid-Open (JP-A) No. 61-5011). And a solubilizing composition which consist of 4 ingredients, tocopherol, sugars, sugar alcohols and polyglycerin unsaturated fatty acid ester is disclosed (JP-A No. 61-234920). A solubilizing solution consisting of 4 ingredients, tocopherol, water, polyol and polyglycerin fatty acid ester is also disclosed (JP-A No. 62-250941). Furthermore, a solubilizing composition consisting of 4 ingredients, tocopherol, sugars, sugar alcohols and polyglycerin fatty acid ester is disclosed (Japanese Patent Application Publication (JP-B) No. 06-36862).
However, there are problems with these proposals. Since extremely large amount of various additives must be added to the tocopherol, it does not match current consumers' needs which are likely to consume small amount of additives and moreover, it is impossible to prevent occurrence of precipitates and lees completely. In addition, it is unfavorable to use as a liquid medication because of strong undesirable taste typical for the additives.
At the same time, a solubilizing solution containing sucrose fatty acid ester as an additive is disclosed besides these proposals. For example, a coloring formulation in which lecithin and polyglycerin fatty acid ester are contained in a system which is emulsified and dispersed with sucrose fatty acid ester is disclosed (JP-A No. 58-103325). However, in this case, the effect of preventing precipitates and lees over time is not mentioned at all.
Moreover, a lipophilic material aqueous solution containing tocopherol, polyglycerin fatty acid ester, sucrose fatty acid ester, polyol and water is disclosed (JP-A No. 2000-212066). Furthermore, a solubilizing solution consisting of 4 ingredients of tocopherol, polyoxyethylene hydrogenated castor oil, polyglycerin fatty acid ester and sucrose fatty acid ester is disclosed (JP-A No. 2002-80365). However, in these cases, sucrose fatty acid ester is not necessary an essential ingredient and the effect of preventing precipitates and lees over time is not mentioned at all.
On the other hand, a liquid medication containing 5 ingredients of tocopherol acetate, polyoxyethylene hydrogenated castor oil, polyglycerin fatty acid ester, sucrose fatty acid ester and glycerin is disclosed (JP-A No. 2002-80347). In this disclosure, however, it is only intended to obtain appropriate dosability by preventing rusty taste originated from bivalent iron ion.
The liquid preparation in which the sucrose fatty acid ester is an essential ingredient and other ingredients are further optimized to prevent precipitates and lees highly effectively even after long storage, contributing to excellent stability and transparency, which is suitable for use in pharmaceutical preparation, cosmetic preparation, foods and drinks are not yet provided in the existing circumstances and the development is strongly desired.